diff --git a/README.md b/README.md
index 9da16e11..e58cd2cb 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@ By _inspect_ I mean it fetches the repository's manifest and it is able to show
 json output about a whole repository or a tag. This tool, in constrast to `docker inspect`, helps you gather useful information about
 a repository or a tag before pulling it (using disk space) - e.g. - which tags are available for the given repository? which labels the image has?
 
-Example:
+Examples:
 ```sh
 # show repository's labels of rhel7:latest
 $ skopeo registry.access.redhat.com/rhel7 | jq '.Config.Labels'
@@ -39,6 +39,48 @@ $ skopeo docker.io/fedora | jq '.RepoTags'
 $ skopeo docker.io/fedora:rawhide | jq '.Digest'
 "sha256:905b4846938c8aef94f52f3e41a11398ae5b40f5855fb0e40ed9c157e721d7f8"
 ```
+
+Private registries with authentication
+-
+When interacting with private registries, `skopeo` first looks for the Docker's cli config file (usually located at `$HOME/.docker/config.json`) to get the credentials needed to authenticate. When the file isn't available it falls back looking for `--username` and `--password` flags. The ultimate fallback, as Docker does, is to provide an empty authentication when interacting with those registries.
+
+Examples:
+```sh
+# on my system
+$ skopeo --help | grep docker-cfg
+   --docker-cfg "/home/runcom/.docker"	Docker's cli config for auth
+
+$ cat /home/runcom/.docker/config.json
+{
+	"auths": {
+		"myregistrydomain.com:5000": {
+			"auth": "dGVzdHVzZXI6dGVzdHBhc3N3b3Jk",
+			"email": "stuf@ex.cm"
+		}
+	}
+}
+
+# we can see I'm already authenticated via docker login and everything will be fine
+$ skopeo myregistrydomain.com:5000/busybox
+{"Tag":"latest","Digest":"sha256:473bb2189d7b913ed7187a33d11e743fdc2f88931122a44d91a301b64419f092","RepoTags":["latest"],"Comment":"","Created":"2016-01-15T18:06:41.282540103Z","ContainerConfig":{"Hostname":"aded96b43f48","Domainname":"","User":"","AttachStdin":false,"AttachStdout":false,"AttachStderr":false,"Tty":false,"OpenStdin":false,"StdinOnce":false,"Env":null,"Cmd":["/bin/sh","-c","#(nop) CMD [\"sh\"]"],"Image":"9e77fef7a1c9f989988c06620dabc4020c607885b959a2cbd7c2283c91da3e33","Volumes":null,"WorkingDir":"","Entrypoint":null,"OnBuild":null,"Labels":null},"DockerVersion":"1.8.3","Author":"","Config":{"Hostname":"aded96b43f48","Domainname":"","User":"","AttachStdin":false,"AttachStdout":false,"AttachStderr":false,"Tty":false,"OpenStdin":false,"StdinOnce":false,"Env":null,"Cmd":["sh"],"Image":"9e77fef7a1c9f989988c06620dabc4020c607885b959a2cbd7c2283c91da3e33","Volumes":null,"WorkingDir":"","Entrypoint":null,"OnBuild":null,"Labels":null},"Architecture":"amd64","Os":"linux"}
+
+# let's try now to fake a non existent Docker's config file
+$ skopeo --docker-cfg="" myregistrydomain.com:5000/busybox  1 ↵
+INFO[0000] Docker cli config file not found: stat : no such file or directory, falling back to --username and --password
+FATA[0000] unable to ping registry endpoint http://myregistrydomain.com:5000/v0/
+v2 ping attempt failed with error: Get http://myregistrydomain.com:5000/v2/: malformed HTTP response "\x15\x03\x01\x00\x02\x02"
+ v1 ping attempt failed with error: Get http://myregistrydomain.com:5000/v1/_ping: malformed HTTP response "\x15\x03\x01\x00\x02\x02"
+
+# we can see the cli config isn't found so it looks for --username and --password
+# but because I didn't provide them I can't auth to the registry and I receive the above error
+INFO[0000] Docker cli config file not found: stat : no such file or directory, falling back to --username and --password
+
+# passing --username and --password - we can see that everything goes fine despite an info showing
+# cli config can't be found
+$ skopeo --docker-cfg="" --username=testuser --password=testpassword myregistrydomain.com:5000/busybox
+INFO[0000] Docker cli config file not found: stat : no such file or directory, falling back to --username and --password
+{"Tag":"latest","Digest":"sha256:473bb2189d7b913ed7187a33d11e743fdc2f88931122a44d91a301b64419f092","RepoTags":["latest"],"Comment":"","Created":"2016-01-15T18:06:41.282540103Z","ContainerConfig":{"Hostname":"aded96b43f48","Domainname":"","User":"","AttachStdin":false,"AttachStdout":false,"AttachStderr":false,"Tty":false,"OpenStdin":false,"StdinOnce":false,"Env":null,"Cmd":["/bin/sh","-c","#(nop) CMD [\"sh\"]"],"Image":"9e77fef7a1c9f989988c06620dabc4020c607885b959a2cbd7c2283c91da3e33","Volumes":null,"WorkingDir":"","Entrypoint":null,"OnBuild":null,"Labels":null},"DockerVersion":"1.8.3","Author":"","Config":{"Hostname":"aded96b43f48","Domainname":"","User":"","AttachStdin":false,"AttachStdout":false,"AttachStderr":false,"Tty":false,"OpenStdin":false,"StdinOnce":false,"Env":null,"Cmd":["sh"],"Image":"9e77fef7a1c9f989988c06620dabc4020c607885b959a2cbd7c2283c91da3e33","Volumes":null,"WorkingDir":"","Entrypoint":null,"OnBuild":null,"Labels":null},"Architecture":"amd64","Os":"linux"}
+```
 Building
 -
 ```sh